addition : Java Glossary

+ is the Java addition operator. There are two addition
operators, integer and floating point, but they both use the same operator symbol.
Integer addition works on byte, char, short, int and long and always results in an
integer, i.e. no fraction. If the results of adding two ints is too big to fit in an int, the
high order bits will be discarded or considered as a sign bit, without any sort of
exception.

Floating point addition works on float and
double. Floating point addition results in a fractional
value that can be represented in IEEE (Institute of Electrical & Electronics Engineers)
format. For maximum accuracy, when you add several numbers together, add the small
ones together first.